The Pyrenean glaciers (South West Europe) in 1850 and 2011: a new cross-border inventory based on aerial images and field surveys
Résumé
The Pyrenees mountain range hosts the southernmost glaciers in Europe (south of 43°N). Some of these glaciers were studied by scientists since the end of the 19th century. However, a comprehensive and accurate inventory of their present-day extent was still missing up to now. The Pyrenean glaciers were classified as “nominal glaciers” in the Randolph Glacier Inventory (RGI Release 4.0). Nominal glaciers are those which are known to exist but are recorded only collectively or approximately in the source inventories. Here we present a new inventory of the Pyrenean glaciers. We used aerial ortho-images with a ground resolution of 0.5 m from the Spanish and French National cartographic institutes acquired in summer 2010 and 2012 to outline all known glaciers in the Pyrenees. This resolution was adapted to the small size of the glacier in the area (< 1 km²). In addition, field surveys helped us to determine or modify glaciers front positions at the end of the 2011 hydrological cycle (i.e. 1st October 2011). From the 107 nominal glaciers that were listed in the RGI v4.0 only 31 glaciers are actual glaciers in 2011. In 1850, the total glaciated area in the Pyrenees was around 20 km2, in 2011 it was 3 km2 according to our latest inventory. This dataset provides a basis to study the fate of the glaciers in the Pyrenees, including the 80 Pyrenean glaciers that vanished from the previous inventories.
Domaines
Glaciologie
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